GI Part 2 Flashcards
branches of coeliac trunk
- common hepatic arteries
- left gastric art
- splenic artery
(+L&R gastro-epiploic arteries)
venous drainage of stomach
left and right gastric vein > hepatic portal vein
left gastroepiploic vein > splenic > hepatic portal
right gastroepiploic > smv > hepatic portal vein
lymph node drainage of stomach (applicable to other structures)
coeliac LN > pre-aortic
SM LN > pre-aortic
IM LN > pre-aortic
JEJENUM vs ILEUM
JEJENUM:
- longer vasa recta,
- less fat
- prominent plicae circulares
ILEUM
- shorter vasa recta; more complex
- more fat
- less plicae circulares
- narrower and thin-walled
Aspects of large intestine
APPENDIX EPIPLOICA
HAUSTRUM / HAUSTRAL FOLDS
TENNIAE COLI
arterial and venous of ascending
R colic arteries and veins
ileocolic arteries and veins
arterial and venous of transverse
L superior colic art.; R and middle colic art
middle, left colic vein
arterial and venous of descending
left colic art. + superior sigmoid art.
IMV
arterial and venous of sigmoid
sigmoid arteries
IMV
arterial and venous of rectume
corresponding SUP/MIDDLE/INFERIOR arteries and veins
all drain to PARA RECTAL NODES > IM LN
role of the pelvic floor?
act as muscular constrictors for anal orifice alongside int. and ext. anal sphincters
what kind of mucosal types exist along the GIT?
protective: oral, pharynx, oesoph., anal canal
secretory: stomach
abs: small intestine
abs/protective: large intestine
cell types in the gastric glands
GASTRIC PIT: surface mucous
ISTHMUS: parietal cells
NECK: neck mucous, stem cells, parietal cells
GASTRIC PIT: peptic, parietal cells, neck mucous cells, neuroendocrine
G cells found in pits in PYLORIC ANTRUM
Histology of small intestines
columnar absorptive found on villi = enterocytes + goblet cells
crypts of lieberkuhn in betweek villi
lamina propria: vasculature abs. products
- lacteals @ lymphatic capillaries
- peyer’s patches
Crypts of L
@ small intestine
floor of the crypts made of lamina propria
Paneth cells: eosinophillic (uniquely duodenal)
endocrine: secretin, somatstatin, serotonin
stem cells: replacing enterocytes
Duodenal histology features
BRUNNERS GLANDS in submucosa
= mucus secretion +mucus from goblets
- broader villi
- less peyers
Large intestine histology
deep crypts w/ columnar abs. cells
+goblets
+ endocrine
+basal stem cells
What forms the internal anal sphincter?
The circular muscles of the muscularis externa running along the L.Int.
Jejenum Vs Ileum
JEJENUM
swollen villi, varying heights
simple arcardes, longer vasa recta
ILEUM
thin villi, less abundant, PROMINENT PEYERS
complex arcades, shorter vasa recta
+fat
Significance @ ano-rectal junction
transition from simple columnar to stratified squamous
What is the portal vein?
@ the porta hepatis
carries nutrient rich blood from s. int.
(made from the joining of the splenic vein + SMV)
What are the hepatic arteries
@ the porta hepatis
oxygenates the liveer from the Ao.
Structures found at the porta hepatis
portal vein
hepatic arteries
hepatic plexus
hepatic duct (carries bile from the liver)
lymphatic vessels
Lymphatic drainage of the liver
ant: hepatic LN (lesser omentum) > colic LN > cisterna chyli
post:
phrenic + post. mediastinal nodes > right. lymphatic + thoracic ducts
